Tapping attachment for boring-machines.



B. W. BRONANDER.

TAPPING ATTACHMENT FOR BORING MACHiNES.

APPLICATJON FILED on. 19. l9l5. RENEWED SEPT. 19. 1916.

1,224,596, Patented May1,1917,

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5 TED STATE PATENT @FFTQEQ BERTIL \VILHELM BRONANDEB, 0E 'BROOKLYN, NEWYORK, ASSIGNOIR. .TO WAHLSTROMe TOOL COMPANY, OF NEW YORK, .N'. Y., A-CORPOR-ATIDNiOF NEW 'YORK.

TAPIPING ATTACHMENT FOR BORING-MACHINES.

Specification of Letters Patent.

Patented May 1, 1917.

Application filed October 19,-1915,'Seria11 To. 56 ,664. Renewed September 19, 1916. SerialiNo. 121,067.

To all whom it may concern:

Be it known that I, BERTIL .WILHELM BRoNANonn,:a citizen of the United States, residing at Brooklyn, county of :Kings,'and State ofNew York,have invented a new and useful Improvement in Tapping Attachments for Boringdviachines, of which the following is a specification.

This invention :relates to an improvement in tapping attachments for boring machines.

In devices heretofore used 'for tapping holes drilled in work by a boring machine, such for instance as a drilltpress, ithas-been customary to employ :manually operated means for effecting. a reversal of the direction of rotation of'the tap. The main 'object of the present invention is'the production of a tapping attachment for boring machines in which the reversal of the tap is effected automatically. A further object of the invention is the production of-a device of this character provided with means for throwing the reversing mechanism out of action so that the device may be used without the reversing mechanism-to effect the tapping cut straight through the work Without reversal when the material is soft enough to permit it. With these and-other objects not specifically mentioned in view,'the invention consists in certain constructions and combinations which will be hereinafter fully described and then specifically set (forth in the claims hereunto appended.

In the accompanying drawings, which form a part of this specification and in which like characters of reference indicate thesame orlike parts, Figure 1 is a viewpartly broken away and partly in section of a device constructed in accordance with the invention; Fig. '2 is a sectional view taken on the line 22 in Fig. 1; Fig. 3 is a constructions, there is also provided means for throwing and holding said reversing mechanism out of action so that a straight out can be made if desired. :In the-best constructions also, there is provided a non-'r0 tatingcasing supporting the reversing-mechanism and inclosing the working'mechanism. In the best constructions also, there is provided a reversing mechanism comprising a train of gears and an automatically operated clutch device for reversing the-driven spindle. Allof theseparts-may be varied in construction within wide limits. The device selectedto illustrate the invention is but one of many possible concreteembodimentsof the same, and the invention thereforeis not'to'be restrictedto the precise-details of the structure shown and described except as-required by the claims.

Referring to the drawings, 1 indicates a driving spindle which is adapted to be attached to a -drill press or other boring-machine. Secured to thedriving spindle 1 by means of a pin 2 is a driving gear 8. This driving gearis ournaled in a boss 4 formed in a two-part casing, the upper part of which'is marked 5, and the lower-part 6,'the two parts being held togetherby means of screws 7. For the purpose of holding this two-part casing in a stationary position during the operation of the device, there is provided a bar-8 secured in a suitable aperture on the parting line of the casing parts 5-43 by means of a set screw 9. In the use of the device this bar may be held by hand or it maybe permitted to rest against some stationarypart of the drill press or boring machine in connection with which the device is used.

There is further provided a driven spindle 1.0 which is in axial alinement with the driving spindle 1 andis provided with a flange 1'1 and an extension 12, which extension is piloted in the driving gear 3 before referred to. The driven spindle 10 is journaled in a boss 13 formed in the lower part 6 of the two-part casing and it will be understood that the two spindles are held in accurate alinement through the agency of the casing and the extension piloted. in the driving gear 3. There is further provided a pair of intermediate gears '14 which are journaled in oppositely disposed bosses 15 formed on the parting'line of'thetwo-part easing 56. Both'of-these gears 14 are in mesh with the driving gear 3 and both are also in mesh with a driven gear 16 which is loosely mounted upon the driven spindle 10 in the lower part of the lower half 6 of the casing. It will be readily understood that the driven gear of this train of gears continuously rotates in a direction opposite to that of the driving gear 3. For the purpose of causing the driving gear 3 and the driven gear 16 to alternately operate the driving spindle clutch mechanism is interposed between said driving and driven gears. This clutch mechanism includes a slidable clutch member 17 which is splined to the driven spindle 10 by means of a spline 18. This construction permits the slidable clutch member 17 tov move longitudinally with respect to the driving spindle 10 but constrains it to rotate with said driving spindle irrespective of its longitudinal position. Upon the lower end of the slidable clutch member 17 is integrally formed a clutch flange 19. Upon the upper end of the slidable clutch member 17 is mounted a detachable clutch flange 20. This clutch flange 20 is provided with two depending lugs 21 having T-heads 22, these T-heads being adapted to engage suitable T-slots formed in the walls of the slidable clutch member 17 A clutch flange 23 is secured to the lower face of the driving gear 3 by means of dowels or pins 241-. This clutch flange 23 is adapted for engagement with the clutch flange 20 of the slidable clutch member. The driven gear 16 carries a clutch flange 25. This clutch flange 25 is not securely fastened to the driven gear 16, but is slidably mounted upon a plurality of studs 26 symmetrically arranged, but only one of which is shown; and bearing against the clutch flange 25, is a series of springs 27 symmetrically arranged but only one of which is shown. This clutch flange 25 is adapted for engagement with the clutch flange 19 integrally formed on the lower end of the slidable clutch member 17. By an inspection of Figs. 2 and 4, it will be readily un. derstood that the parts are so positioned that the slidable clutch member 17 cannot be in engagement with the clutch flanges 23 and 25 at the same time.

For the purpose of normally holding the slidable clutch member 17 in its uppermost position where the clutch flange 20 is in engagement with the clutch flange 23, there is provided a helical spring 28 coiled around the driven spindle 10 and bearing against the driven gear 16 and the slidable clutch member 17.

The device is provided with means for au tomatically forcing the slidable clutch member 17 down out of engagement with the clutch flange 23 and into engagement with the clutch flange 25 at stated intervals. This means onsists of a cam device including in part a sleeve 29 loosely mounted upon the exterior of the main body of the slidable clutch member 17 This sleeve is provided with a slot 30 the sole purpose of which is to permit the T-headed lugs 21 of the clutch flange 20 to pass into engagement with the walls of the slidable clutch member 17 after the sleeve has been assembled upon said slidable clutch member. The sleeve 29 is provided with a pair of cam' surfaces 31 and these cam surfaces are engaged by cam blocks 32, each of which has an elongated stem 33 fitting a suitable aperture eccentrically positioned in one of the intermediate gears 14; and each block 32 is further provided with a dowel-34 engaging another aperture of. one of the intermediate gears 14. It will be understood that by this construction the cam blocks 32 have a planetary movement around the axes of the intermediate gears and come into contact with the cam surfaces 31 once during each revolution of the intermediate gears; and it will be further understood that when this occurs the slidable clutch member 17 is forced clownwardly against the resistance of the spring 28, is declutched from the driving gear and clutched to the driven gear, which in turn reverses the direction of rotation of the driven spindle. It will be readily understood too that when the cam block 32 rides off of the cam surfaces 31, the spring 28 declutches the slidable clutch member 17 from the driven clutch flange and clutches it with the driving clutch flange.

If the high points on the clutch flanges 19 and 25 should happen to meet just as the cams 32 force the sleeve 29 and slidable clutch member 17 downwardly, the clutch flange 25 will yield against the upward thrust of the springs 27, which springs will of course return the flange 25 to its normal position as soon as the two clutch flanges 19 and 25 have become properly engaged. This prevents the possibility of breakage due to the positive movement of the cam blocks 32.

In cases where the material to be tapped is soft enough to permit of a straight out being made right through the work, it is desirable that the reversing mechanism be thrown out of action. The device selected to illustrate the invention is provided with mechanism for this purpose. Vith this end in View, the sleeve 29 is provided with a slot 35. This slot is engaged by a roller 36 mounted upon a stud 37 formed eccentrically upon a flange 38. This flange 38 is housed in the casing 5 6 before referred to and is provided with a projecting stem 39 upon which a turning knob 40 is secured by means of a pin 41. A spring 42 is provided and is located within the casing and bears cutin the'casing 5'6. The functionofthe spring 42 is to-hold these lugs 43 in engagement with the slots 44: in either of'two positions. One of these positions is shown in Fig. '1 and when the .parts are in this position, the reversing mechanism is in operation. Another position isillustrated in Fig. 3 and whenthe parts are in this position, the reversing mechanism is out of action beeause'the cam surfaces 31 havebeenmoved out of the path of movement of the cam blocks 32.

After a hole has been completely tapped, either with orwithout the use of the automaticreversing mechanism, the whole device is lifted by means of the feed lever on the drill press or other boring machine inconnection with which the device 'is used. The tap being in engagement "with the threads just cut in the workiprevents the spindle 10 from rising, but the driving spindle and the casing rise. During this action the flange 11 of the driven spindle 10 operates to prevent the slidable clutch member 17 from rising with the main body of the device and thereby effects the declutching of the 'slidable clutch member fromthe driving gear clutch flange and throws it into engagement with the driven gear clutch flange. This ofcourse causesa reversal of the direction of rotation ofthe drivenspindle and the tap carried thereby, and 'the tap therefore isbacked out of the work.

In'view of the foregoing, a more detailed description of the operation of th'e'device is deemed unnecessary and'is therefore omitted in the interest'of brevity.

What is claimed is:

1. In a tapping attachment for boring machines, the combination with a driving spindle, of'adriven spindle, reversing meclr anism associated with both of said spindles, automatically operativemeans for actuating said reversing mechanism at rapidly recurring intervals during the tapping operation to alternately rotate the driven spindle in opposite directions the forward rotation of the driven spindlebeing in excess-of thereverse rotation, and a non-'rotating casing supporting the reversing mechanism.

2. In a tapping attachment for boring machines, the combination with a driving spindle, of a driven spindle, reversing mechanismi associated .with both of *said spindles, automatically operative means for actuating said reversing mechanism at rapidly recurring intervals duringthe tapping operation to alternately rotate the driven spindle in opposite-directions the forward rotation of the driven spindle being in ex cess f the reverse rotation, anda two-part non-rotating casing supporting "the reversin g mechanism.

3. In a tapping attachment for boring machines, the combination with a driving &

spindle, ofa driven spindle, reversing mechanism associated with both of said spindles, automatically operative means for actuating said reversing mechanism at rapidly recurring intervals duringthe tapping operationtoalternately rotate the driven spindle in'opposite directions the forward rotation ofthe driven-spindle being in GXCGSSOf the reverse rotation, means for throwing and holding the reversing mechanism out'of action, and a casing supporting the reversing mechanism and the means for throwing the reversing mechanism out of action.

4:. In a tapping attachment for boring machines, the combination with a driving spindle of-a driven spindle in axial alinement with the driven spindle, reversing Inech'anism associated with both of said spindles, and automaticallyoperative means for actuating said reversing mechanism at rapidly recurring intervals during the tapping operation to alternately rotate the driven spindle in opposite Qll'GCtlOIlS the forward rotation of the driven spindle being IH'BXCGSS of the reverse rotation.

5. In a tapping attachment for boring machines, the combination with a driving spindle,'of adriven spindle, reversing mechanism associated with both of said spindles and comprising a train of gears'and a clutch device, and automatically operative means for actuating said clutch device at rapidly recurring intervals duringthe tappin operation to cause the reversing mechanism to alternately rotate the driven spindle in opposite directions the forward rotation of the driven spindle being in excess of the-reverse rotation.

6. In a tapping attachment for boring machines, the combination with a driving spindle,'of a driven spindle, reversing mechanism associated with both of said spindles and'com'prising atrain of gears and'a clutch device, and automatically operative means in part carriedand operated'by one of the gears for actuating said reversing mechanism at rapidly recurring intervals during the tapping operation to alternately rotate the driven spindle-in opposite directions the forward rotation of the driven spindle bein in excess ofthe reverse rotation.

In a tapping attachment for boring machines, the combination with a driving spindle, of a driven spindle, reversing mechanism associated withboth of said spindles and comprising a train of gears and a clutch device, and an automatically operative cam device foractuating said reversing mecha nism'at rapidly recurring intervalsduring the tapping operation to alternately rotate the drivenspindle in opposite directions the forward rotation of the driven spindle be ing inexcess of the reverse rotation.

8. In a tapping attachment for boring machines, the combination with a driving spindle, of a driven spindle, reversing mechanism associated with both of said spindles and comprising a train of gears and a clutch device, and an automatically operative cam device in part carried by one of the gears for actuating said reversing mechanism at rapidly recurring intervals during the tapping operation to alternately rotate the driven spindle in opposite directions the forward rotation of the driven spindle being in excess of the reverse rotation.

9. In a tapping attachment for boring machines, the combination with a driving spindle, of a'driven spindle, a casing, reversing mechanism located within and supported by the casing and associated with both of said spindles and comprising a train of gears and a clutch device part of the gears being journaled in the casing and part mounted upon the spindles, and automatically operative means for actuating said reversing mechanism at rapidly recurring intervals during the tapping operation to alternately rotate the driven spindle in opposite directions the forward rotation of the driven spindle being in excess of the reverse rotation.

10. In a tapping attachment for boring machines, the combination with a driving spindle, of a driven spindle in axial alinement with the driving spindle, reversing miechanism associated with both of said spindles and comprising a slidable clutch member splined to the driven spindle and a train of gears two of which carry clutch members adapted for alternate engagement with the slidable clutch member, and automatically operative means for actuating said reversing mechanism at rapidly recurring-intervals during the tapping operation to alternately rotate the driven spindle in opposite directions the forward rotation of the driven spindle being in excess of the reverse rotation.

11. In a tapping attachment for boring machines, the combination with a driving spindle, of a driven spindle, reversing mechanism associated with both of said spindles and comprising a slidable clutch member splined to the driven spindle and a train of gears two of which carry clutch members adapted for alternate engagement with the slidable clutch member, a cam sleeve mounted upon the slidable clutch member, a spring for normally holding the slidable clutch member in engagement with one of the gear clutch members, and means carried by two of the gears for actuating the cam sleeve and slidable clutch member to throw the latter out of engagement with one of the clutch members and into engagement with the other.

12. In a tapping attachment for boring machines, the combination with a driving spindle, of a driving gear carried by said driving spindle, a driven spindle in axial alinement with the driving spindle and piloted in the driving gear, a driven gear loosely mounted upon the driven spindle, a pair of intermediate gears in mesh with the driving gear and driven gear, a pair of clutch members one carried by the driving gear and one carried by the driven gear, a slidable clutch member splined to the driven spindle between the driving gear and driven gear and adapted for alternate engagement with the clutch members carried by said gears, a cam sleeve carried by the slidable clutch member, a spring for normally holding the slidable clutch member in engagement with the driving gear clutch members, and cam devices carried by the intermediate gears for operating the cam sleeve to longitudinally move the slidable clutch member out of engagement with the driving gear clutch member and into engagement with the driven gear clutch member.

13. In a tapping attachment for boring machines, the combination with a driving spindle, of a driving gear carried by said driving spindle, a driven spindle in axial alinement with the driving spindle and piloted in the driving gear, a driven gear loosely mounted upon the driven spindle, a pair of intermediate gears in mesh with the driving gear and driven gear, a pair of clutch members one carried by the'driving gear and one carried by the driven gear, a slidable clutch member splined to the driven spindle between th driving gear and driven gear and adapted for alternate engagement with the clutch members carried by said gears, a cam sleeve carried by the slidable clutch member, a spring for normally holding the slidable clutch member in engagement with the driving gear clutch members, cam devices carried by the intermediate gears for actuating the cam sleeve to longitudinally movethe slidable clutch member out of engagement with the driven clutch member and into engagement with the driven clutch member, and means for rotating the cam sleeve to prevent its engagement by the intermediate gear cam devices.

14. In a tapping attachment for boring machines, the combination with a driving spindle, of a driving gear carried by said driving spindle, a driven spindle in axial alinement with the driving spindle and piloted in the driving gear, a driven gear loosely mounted upon the driven spindle, a

pair of intermediate gears in mesh with the driving gear and driven gear, a pair of clutch members one carried by the driving gear and one carried by the driven gear, a slidable clutch member splined to the driven spindle between the driving gear and driven gear and adapted for alternate engagement with the clutch members carried by said gears, a cam-sleeve carried by the slidable clutch member, a spring for normally holding the slidable clutch member in engagement With the driving gear clutch member, cam devices carried by the intermediate gears for actuating the cam sleeve to longitudinally move the slidable clutch member out of engagement With the driving gear clutch member and into engagement With the driven gear clutch member, and an eccentric device for rotating the cam sleeve to prevent its engagement by the intermediate gear cam devices.

15. In a tapping attachment for boring machines, the combination with a driving spindle, of a driving gear carried by said driving spindle, a driven spindle in axial alinement With the driving spindle and piloted in the driving gear, a driven gear loosely mounted upon the driven spindle, a

pair of intermediate gears in mesh with the driving gear and driven gear, a pair of clutch members one carried by the driving gear and one carried by the driven gear, a slidable clutch member splined t0 the driven spindle between the driving gear and driven gear and adapted for alternate engagement With the clutch members carried by said gears, a cam sleeve carried by the slidable clutch member, a spring for normally holding the slidable clutch member in engagement with the driving gear clutch member, cam devices carried by the intermediate gears for actuating the cam sleeve to longitudinally move the slidable clutch member out of engagement with the driving gear clutch member and into engagement With the driven gear clutch member, an eccentric device for rotating the cam sleeve to prevent its engagement by the intermediate gear cam devices, and a casing inclosing the gear and clutch members and the eccentric device and supporting the intermediate gears.

In testimony whereof, I have signed my name to this specification in the presence of tWo subscribing Witnesses.

BERTIL WILHELM BRONANDER.

Witnesses:

SYDNEY I. PRESCOTT, ELIZABETH LOUISE RUSSELL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

